Desktop background image extension?

[David Barrett <dbarrett quinthar com>]

Hi, I'm making the switch from Mac to Ubuntu and one of the few features 
I miss is the ability to automatically set my desktop background image 
to a random picture from my iPhoto library.  Does something like this 
already exist for F-Spot, or how would you recommend I go ahead and 
build it?

I see you use SQLite under the hood; would the easiest/recommended way 
be to just create a Cron script that:

1) Opens that database
2) Picks a random "favorite" image
3) Updates the desktop background
4) Exits

Or, is this something better done as an extension?

Thanks for the great tool, and I'm curious how I can help!

-david